Notes from Sund  ·  Issue 02  ·  September 2026

Hi {{first_name}},

Last week I had a blast taking part in the Canine Behaviour College reactivity challenge, a fantastic teaser for the clinical canine behaviour degree I start in October. It was all about diving deep into the science behind why our dogs react the way they do, and how we can help them retrain their brains.

This issue

The drama almond, and what is actually happening when your dog reacts

Here is the science made simple. When your dog explodes on the lead, they aren't choosing to be 'bad' or 'stubborn'. Think of it as a biological hiccup. Their brain's primal alarm centre, the amygdala, or the 'drama almond', as the CBC aptly nicknames it, triggers an immediate survival reflex before the rational, thinking part of the brain, the prefrontal cortex (the brain's 'librarian'), has a chance to weigh in. When daily stress builds up, the bin lorry, the doorbell, the neighbour's dog barking through the fence, a slippery floor, it is like filling a bucket: this is 'trigger stacking', which pushes cortisol (the primary stress chemical) to high levels, eventually making the bucket overflow which leads to the reactive response.

Because a panicked brain cannot learn, real progress isn't about corrections; it is about using the brain's amazing ability to rewire itself, called neuroplasticity. By keeping our dogs 'sub-threshold' meaning they are relatively calm and can see their trigger without panicking, we keep their cognitive circuits online. We are teaching them to associate that scary thing with something great, like treats, to help them build a new, reliable 'brake' over that alarm system.

Proactive management, like avoiding those overwhelming situations, isn't admitting defeat; it is a brilliant, active strategy. It is our way of protecting their nervous system from those nasty cortisol spikes. When the unexpected happens, having an 'escape toolkit' is a lifesaver. Tossing treats in the grass with a 'find it' cue uses the nose to calm the brain, boosting dopamine (the feel-good chemical) and lowering stress. And a quick, practised 180-degree U-turn is like a magic spell, turning a potential panic moment into a fun, rewarding game of motion.

Written after the Canine Behaviour College reactivity challenge, August 2026. Sources at the end of this issue.

I am beyond excited to get stuck into these topics when I start my degree in October, and I will bring back what I learn. More research in the next issue.

Renske

Founder, Sund  ·  sund.dog

Sources

Worth being clear about where the evidence sits: the stress physiology is well established, while the bucket and threshold models come from applied training practice rather than from a single controlled study.

Modular organization of the brainstem noradrenaline system coordinates opposing learning states — Uematsu, A., Tan, B.Z., Ycu, E.A., Sulkes Cuevas, J., Koivumaa, J., Junyent, F., Kremer, E.J., Witten, I.B., Deisseroth, K. & Johansen, J.P.

Noradrenergic modulation of fear conditioning and extinction — Giustino, T.F. & Maren, S.

Neuroendocrinological regulation to stress response in domesticated canines — Bhansali, K.

What's in a brain: neuroanatomy and neurochemistry of anxiety disorders in dogs — Vermeire, S., Audenaert, K., Vandermeulen, E. & De Meester, R.

The angry brain: a neuroscientific expedition into the depths of canine aggression — De Gols, B.

Genetic mapping of canine fear and aggression — Zapata, I., Serpell, J.A. & Alvarez, C.E.

Nuclear medicine for the investigation of canine behavioral disorders — Taylor, O., Audenaert, K., Baeken, C., Saunders, J. & Peremans, K.

Abnormal repetitive behaviors in dogs and cats: a guide for practitioners — Tynes, V.V. & Sinn, L.